Electric aural apparatus more especially for use by deaf persons



Mar. 3, 1925. 1,528,602

- s. (5'. BROWN ELECTRIQ AURAL APPARATUS MORE ESPECIALLY FOR USE BY DEAF PERSONS Filed 061). 24, 1921 I mmntar.

Patented Ma. 3, 1925.

UNITED STATES PATENT I OFFICE.

snmny ononon nao'wn, or wnnmnnn LANE, non'rn ACTON, ENGLAND.

mnornrcaomr. APPARATUS moan nsrncmrnv FOR USE BY DEAF rnnsons.

Application filed October 24, 1921. Serial No. 510,931.

more especially for use by deaf persons, and

has for its chief object to provide an improved construction whereby thesound is transmitted in a highly eflicient manner through to the skull or teeth by a vibrating member.

In order that the said invention may be clearly understood and readily carried into efi'ect, the same will now be described more fully with reference to the accompanying drawings, in which Figure 1 is a longitudinal section and Figure 2 is a plan, with cover removed, of a sound transmitting device embodying this invention. x

A is the casing with removable cover a.

B is a horse-shoe permanent magnet having poles in the form of a single pole-piece b which extends across the ends of the magnet, the pole-piece being preferably made from a single plate formed. with ar'holeor gap 6' leaving narrow connectingv bars at each side. C is a stiifreed made of considerable rigidity and mounted at its inner end upon the base D fitted within the casing A, the reed being secured upon theproj ection or column d of the base by the screws 0. E is a sound transmitting contact stud, which is shown-fixedgupon the outer end'o-f the ,ieed outside the casing. F, F are a pair of small electro-magnets on the polepiece I), the coils of which magnets are connected to the sockets a in the insulating block a? on the bottom of the casing A, the wires f passing through a hole (1 in the base D.

The reed C possesses considerablerigidity, so that its oscillations are of small amplitude and of relatively large power, the reed when secured in place lying immediately above but not uite in contact with the pole-piece b above t 6 gap 6 The permanent magnet is preferably made strong so as to exercise substantial attraction upon the reed but the screws 0 secure the reed so that it does not come into actual contact with the poleiecc. 'lhe electro-magrrets F are connecte up through the sockets a to the telephone transmitter of any suitable character, so that the speech currents cause variations in the magnetic field through the soft iron or steel polo-piece 6, giving rise to'corresponding vibrations of the stiff reed C. the natural period of which may be considerably above the periods of ordinary speech currents.

The outer end of the reed C projects through a gap a in the casing A and the stud E, which may be of vulcanite, is secured upon the end of the reed so as to project clear of the casing. 'Theposition of the stud on the reed may be varied and may be placed 'be'tween the electro-magnets and the mounting of the reed, in which case the stud might project through the top of the casing. However mounted, the stud must be in a convenient position for application to the teeth or to the skull of the person using the apparatus, so that the small amplitude but relatively powerful vibrations of the reed are transmitted directly to the bones of the head and consequently to the inner ear independently of the ear drum. As the conduction of sound is not through the air but is through solid bodies a small amplitude of vibration is sufficient to produce the loud sounds required and the rigidity or stiffness of the reed C is therefore an essential feature, a weak reed having vibrations of large amplitude but relatively small power which would "be ineffective as applied to the teeth or skull of the deaf per-' son for whom the device is especially intended.

What I claim and desire to secure by Letters Patent of the United States is 1. In an electrical aural device, the combination comprising a magnet, a pole piece joining the two ends of saidmagnet, energizing coils therefor, a stiff vibrating member rigidly fixed at one end and in operative juxtaposition to said pole piece and a sound-conducting member mounted upon the free end of said vibrating member for conveying sound vibrations to deaf persons otherwise than by '-the ear drum, as set one end and situated over the hoie in said forth. pole piece and a. sound eonductin member 2. In an electrical aural device, the com- :mounted upon thefree end of saig reed for 10 bination comprising a. horse-shoema et, a conveying sound vibrations to deaf persons 1 5 pole piece joining the two ends of sei magotherwise than by the ear drum, as set forth.

net and having a hole therein, energizing coils therefor, a stiff reed rigidly secured at SIDNEY GEORGE BROWN. 

